Live coverage of Wallops’ first launch to the International Space Station

We've got a live stream set for today's 10:50am Eastern launch.

Today, Orbital Sciences (the company that sent LADEE to the Moon) is currently in the countdown for its first launch of a supply vessel to the International Space Station. The launch will involve the company's Cygnus capsule coupled to an Antares rocket, and it's scheduled for 10:50am EDT today. NASA TV will be streaming it live, and we've embedded the video below. The photographer who covered the LADEE launch will be on hand for this event as well, so stay tuned for more photos later today.

You can check NASA's website for more information on Orbital Sciences' ISS supply program.

So that's why the ISS was over Indian ocean when they launched from Wallops?

Not quite. Wallops Island is at 37.9 degrees N, whereas the ISS orbits at a 51.6 degree inclination (matching the latitude of Baikonur Cosmodrome). So in order to inject the spacecraft into the correct orbital plane, the launch is scheduled for when the orbital plane of the ISS intersects the launch site, not when the ISS itself passes over the launch site.

Launches from Baikonur are always in-plane, so the Russians can target the phase angle and inject the spacecraft quite closely behind the ISS, enabling the new 6-hour rendezvous profile. But launches from other sites, including Wallops and Cape Canaveral, have daily launch opportunities subject to periodic blackouts when the in-plane phase angle is too large to allow for a timely rendezvous.

Mission planners target the rendezvous timeline by controlling how quickly the spacecraft closes with the ISS from behind, consuming the phase angle. The spacecraft approaches more quickly in a lower orbit or more slowly in a higher orbit. As the spacecraft closes, a series of orbit raising maneuvers reduce the closing velocity until the spacecraft matches the position and velocity of the ISS.

This maiden flight of Cygnus will use a higher phasing orbit to allow more time for system checkouts and for the resolution of any anomalies that might be encountered on orbit.

196 posts | registered Jan 28, 2007

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